From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dinh Nguyen Subject: Re: [PATCH V8 1/2] mtd: spi-nor: Bindings for Cadence Quad SPI Flash Controller driver. Date: Thu, 4 Feb 2016 11:04:08 -0600 Message-ID: <56B38488.2000502@opensource.altera.com> References: <1452486886-8049-1-git-send-email-marex@denx.de> <201602012213.46740.marex@denx.de> <56B30007.1010305@ti.com> <201602041225.11679.marex@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201602041225.11679.marex-ynQEQJNshbs@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Marek Vasut , Vignesh R Cc: Brian Norris , Rob Herring , "linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Graham Moore , Alan Tull , David Woodhouse , Yves Vandervennet , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: devicetree@vger.kernel.org On 02/04/2016 05:25 AM, Marek Vasut wrote: > On Thursday, February 04, 2016 at 08:38:47 AM, Vignesh R wrote: >> On 02/02/2016 02:43 AM, Marek Vasut wrote: >>> On Monday, February 01, 2016 at 10:03:35 PM, Brian Norris wrote: >>>> On Wed, Jan 13, 2016 at 03:39:17AM +0100, Marek Vasut wrote: >>>>> On Wednesday, January 13, 2016 at 03:26:08 AM, Rob Herring wrote: >>>>>> On Mon, Jan 11, 2016 at 05:34:45AM +0100, Marek Vasut wrote: >> [...] >> >>>>> All these SoCs should be capable of tweaking the block to fit their >>>>> needs by just the DT properties. I believe they differ only in the >>>>> FIFO depth and sometimes someone is greedy and uses 4:16 CS >>>>> multiplexer, which is an external passive component, but that's all. >>>>> >>>>> Would we need soc-specific compatible strings if this is the case? >>>> >>>> It's nice when most things can be supported with a small set of DT >>>> properties, as you've done. But IUIC, I think it's usually good practice >>>> to define and use SoC-specific (or maybe SoC family) compatible strings >>>> in the docs and DTS files, in addition to the generic one, in case there >>>> are future quirks that need to be handled. Note that you don't actually >>>> have to use these in the driver yet, but it's good to have a definition. >>>> >>>> So you can, today, have: >>>> foo@xxxx { >>>> >>>> compatible = "ti,baz-12345", "cdns,qspi-nor"; >>>> ... >>>> >>>> }; >>>> >>>> And we have the option to pick up "ti,baz-12345" in the Linux driver *if >>>> needed.* >> >> The support for TI SoC that has this IP is not in upstream yet. I will >> add TI-specific compatible later. It will be: >> >> foo@xxxx { >> compatible = "ti,k2g-qspi", "cdns,qspi-nor"; >> ... >> }; > > Do you expect any specifics which cannot be handled by the current bindings btw? > In my socfpga case, the compatible strings will be probably: > > "altr,socfpga-gen5-qspi" > > Dinh, Graham, do you agree with this or should we use something else ? > I agree. Dinh -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-bl2on0062.outbound.protection.outlook.com ([65.55.169.62] helo=na01-bl2-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aRNRQ-0005ee-JB for linux-mtd@lists.infradead.org; Thu, 04 Feb 2016 17:11:37 +0000 Message-ID: <56B38488.2000502@opensource.altera.com> Date: Thu, 4 Feb 2016 11:04:08 -0600 From: Dinh Nguyen MIME-Version: 1.0 To: Marek Vasut , Vignesh R CC: Brian Norris , Rob Herring , "linux-mtd@lists.infradead.org" , Graham Moore , Alan Tull , David Woodhouse , Yves Vandervennet , "devicetree@vger.kernel.org" Subject: Re: [PATCH V8 1/2] mtd: spi-nor: Bindings for Cadence Quad SPI Flash Controller driver. References: <1452486886-8049-1-git-send-email-marex@denx.de> <201602012213.46740.marex@denx.de> <56B30007.1010305@ti.com> <201602041225.11679.marex@denx.de> In-Reply-To: <201602041225.11679.marex@denx.de> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 02/04/2016 05:25 AM, Marek Vasut wrote: > On Thursday, February 04, 2016 at 08:38:47 AM, Vignesh R wrote: >> On 02/02/2016 02:43 AM, Marek Vasut wrote: >>> On Monday, February 01, 2016 at 10:03:35 PM, Brian Norris wrote: >>>> On Wed, Jan 13, 2016 at 03:39:17AM +0100, Marek Vasut wrote: >>>>> On Wednesday, January 13, 2016 at 03:26:08 AM, Rob Herring wrote: >>>>>> On Mon, Jan 11, 2016 at 05:34:45AM +0100, Marek Vasut wrote: >> [...] >> >>>>> All these SoCs should be capable of tweaking the block to fit their >>>>> needs by just the DT properties. I believe they differ only in the >>>>> FIFO depth and sometimes someone is greedy and uses 4:16 CS >>>>> multiplexer, which is an external passive component, but that's all. >>>>> >>>>> Would we need soc-specific compatible strings if this is the case? >>>> >>>> It's nice when most things can be supported with a small set of DT >>>> properties, as you've done. But IUIC, I think it's usually good practice >>>> to define and use SoC-specific (or maybe SoC family) compatible strings >>>> in the docs and DTS files, in addition to the generic one, in case there >>>> are future quirks that need to be handled. Note that you don't actually >>>> have to use these in the driver yet, but it's good to have a definition. >>>> >>>> So you can, today, have: >>>> foo@xxxx { >>>> >>>> compatible = "ti,baz-12345", "cdns,qspi-nor"; >>>> ... >>>> >>>> }; >>>> >>>> And we have the option to pick up "ti,baz-12345" in the Linux driver *if >>>> needed.* >> >> The support for TI SoC that has this IP is not in upstream yet. I will >> add TI-specific compatible later. It will be: >> >> foo@xxxx { >> compatible = "ti,k2g-qspi", "cdns,qspi-nor"; >> ... >> }; > > Do you expect any specifics which cannot be handled by the current bindings btw? > In my socfpga case, the compatible strings will be probably: > > "altr,socfpga-gen5-qspi" > > Dinh, Graham, do you agree with this or should we use something else ? > I agree. Dinh